Why Book “Exchanges” Don’t Work

So you’ve been invited to participate in a “book exchange”.  It’s easy!  All you have to do is send one book to someone and you’ll get 36 in return!  What a great way to build your library!  I know what you’re thinking.  “Hey, I can send one book.  No problem.  Minimal investment from me and it sounds like fun!  I have six friends, easy peasy.  I’ll only pick people that definitely are interested.  My friends will follow through.”

For the sake of argument, let’s say everyone is completely honest and will follow through if they agree to participate.  Let’s call each layer a “round” and do the math.  

Round	# of participants
1	1	The person that sent you the invite
2	6	You + the 5 other people the invite was sent to
3	36	Your 6 friends, and the others 6 friends
4	216	36 of these people will send an item to you
5	1,296	216 of these people will send an item to the 6 people you recruited
6	7,776
7	46,656
8	279,936
9	1,679,616
10	10,077,696	8,245,000 - Population of New York City
11	60,466,176
12	362,797,056	313,900,000 - Population of the United States
13	2,176,782,336
14	13,060,694,016	6,974,000,000 - Population of Earth

So in the best case scenario, after only 14 rounds, the entire population of the entire world will have had to participated twice for this to be successful.  

Now let’s come back to reality.  

1.  Odds are your friend isn’t the one that started the chain since I’ve seen this floating around for years.  It’s already been passed around to thousands of people.  

2.  Most people aren’t going to follow through. Even if they signed up and agreed to partake, they probably either aren’t going to send a book/letter/dollar/postcard to the person at the top of the list and/or they aren’t going to successfully recruit six new people to join in.

3.  This may be fun and work out for a very few people.  It is very manageable for the first 5 to 6 rounds.  In other words, it’s fun for those that are at the top of the pyramid. But then those further down the chain are going to find it difficult to recruit every person on the planet and be left with nothing.  The math doesn’t hold up.  

Save yourself the frustration: Buy yourself a book and kindly decline to be part of the “exchange”.